Contraction Time Research Articles

Echocardiographic Detection of Subclinical Left Ventricular Dysfunction in Asymptomatic Type Two Diabetes Mellitus

Background: Before systolic dysfunction and symptomatic heart, diabetic cardiomyopathy begins with left ventricular diastolic dysfunction (LVDD). Echocardiographic modalities were used to detect subclinical LV impairment in asymptomatic type 2 diabetics. This study aimed to identify subclinical left ventricular impairment in asymptomatic patients with type two diabetes using several echocardiographic techniques. Methods: In the present prospective cohort study, 30 adults over 18 having type II diabetes mellitus (DM) (Group I) and 20 normal controls (Group II) were studied. Transthoracic echocardiography and 12-lead ECG were performed on all individuals. Results: Pulsed wave Doppler techniques revealed significant variation in transmitral flow velocities between groups, including septal e', lateral mitral annulus early velocity (e'), septal early diastolic peak flow velocity (E)\e', Lateral E\e', and average E\e'. EF was significantly decreased in group I (P < 0.001). With a p-value of 0.001, LVESD was significantly higher in group I. The septal, lateral, and average systolic mitral annulus (S') motions in group II were significantly larger than those in group I. When comparing groups, I and II, the first showed much longer myocardial performance index (MPI) and isovolumetric contraction time (IVCT). The ET for Group I was significantly lower than that of Group II. The study group exhibited significantly greater levels of fasting blood sugar, post-prandial blood sugar, and haemoglobin A1C (HBA1C) compared to the control group (P <0.001). Conclusions: Patients having diabetes mellitus exhibited considerably greater levels of DM history fasting glucose levels, postprandial glucose levels, haemoglobin A1C (HBA1C), E/e´ ratio, LVESD, IVCT, and MPI, while having significantly lower EF and ET relative to the healthy group.

Role of fetal cardiac assessment in predicting adverse perinatal outcomes in preterm dichorionic twins

Aim: To investigate the role of the fetal modified myocardial performance index (Mod-MPI) and fetal cardiac output index measurement in predicting adverse perinatal outcomes among preterm dichorionic twins. Materials and Method: This prospective cohort study was conducted at the X Clinic and included 34 dichorionic twin fetuses born early preterm and 40 dichorionic twin fetuses born late preterm. The early preterm group was divided into two according to whether they were admitted to the neonatal intensive care unit (NICU). The groups' cardiac function and Mod-MPI measurements were compared regarding their predictive ability for adverse perinatal outcomes. Results: The Mod-MPI values were similar between the early and late preterm groups (p=0.144). The left ventricular cardiac output Z-score was lower in the preterm group (p=0.014). The Mod-MPI and left ventricular outflow tract-isovolumetric contraction and isovolumetric relaxation times were significantly higher among the newborns admitted to the NICU in the early preterm group (p=0.002, p=0.003, and p=0.001, respectively). Conclusion: Our study suggests that the Mod-MPI measurement can be used to predict adverse perinatal outcomes in dichorionic twin fetuses born in the early preterm period.

Acute Responses to Traditional and Cluster-Set Squat Training With and Without Blood Flow Restriction.

Cornejo-Daza, PJ, Sánchez-Valdepeñas, J, Páez-Maldonado, J, Rodiles-Guerrero, L, Boullosa, D, León-Prados, JA, Wernbom, M, and Pareja-Blanco, F. Acute responses to traditional and cluster-set squat training with and without blood flow restriction. J Strength Cond Res 38(8): 1401-1412, 2024-To compare the acute responses to different set configurations (cluster [CLU] vs. traditional [TRA]) under distinct blood flow conditions (free vs. restricted) in full-squat (SQ). Twenty resistance-trained males performed 4 protocols that differed in the set configuration (TRA: continuous repetitions; vs. CLU: 30 seconds of rest every 2 repetitions) and in the blood flow condition (FF: free-flow; vs. blood flow restriction [BFR]: 50% of arterial occlusion pressure). The relative intensity (60% 1RM), volume (3 sets of 8 repetitions), and resting time (2 minutes) were equated. Mean propulsive force (MPF), velocity (MPV) and power (MPP), and electromyography (EMG) parameters were recorded during each repetition. Tensiomyography (TMG), blood lactate, countermovement jump (CMJ) height, maximal voluntary isometric contraction, in SQ, and movement velocity against the load that elicited a 1 m·s -1 velocity at baseline (V1-load) in SQ were assessed at pre- and post-exercise. The CLU protocols allowed a better maintenance of MPF, MPV, MPP, and EMG median frequency during the exercise compared to TRA (clu-time interaction, p < 0.05). The TRA protocols experienced greater impairments post-exercise in TMG- and EMG-derived variables (clu-time interaction, p < 0.05) and SQ and CMJ performance (clu-time interaction, p = 0.08 and p < 0.05, respectively), as well as higher blood lactate concentrations (clu-time interaction, p < 0.001) than CLU. Moreover, BFR displayed decreases in TMG variables (bfr-time interaction, p < 0.01), but BFR-CLU resulted in the greatest reduction in twitch contraction time ( p < 0.001). Cluster sets reduced fatigue during and after the training session and BFR exacerbated impairments in muscle mechanical properties; however, the combination of both could improve contraction speed after exercise.

How far shall the protection of a traffic accident victim go under motor third party liability insurance?

This paper was inspired by a recent reference for a preliminary ruling lodged by the French Cour de Cassation (Mutuelle assurance des travailleurs mutualistes (Matmut) v TN and Others, Case C-236/23). The Cour de Cassation asked whether ‘Articles 3 and 13 ofDirective 2009/103 ofthe European Parliament and oftheCouncil of16 September 2009 must be interpreted as precluding the nullity of a contract for civil liability motor insurance from being declared enforceable against a passenger who is a victim where that person is also the policyholder and intentionally made a false statement atthe time of conclusion ofthe contract which gave rise to that nullity’. The Cour de Cassation observed that the CJEU had never ruled whether thenullity ofthe contract can be relied on against a victim who was a passenger in the vehicle where the victim is also the policyholder and the person who made the intentional false statement, which resulted in the insurance contract being null and void under national law. None ofthe judgments delivered by theCJEU relate to that specific situation. Even though the Court has been strengthening the rights of victims oftraffic accidents for many years, by applying arigorous interpretation oftheprovisions ofthemotor insurance directives precluding national rules that would allow for theavoidance ofapolicy response towards apassenger beyond the scope ofthe exclusions expressly allowed in the directives, some questions remain. In this case, we are dealing with an obvious insurance fraud committed by a person who subsequently suffered injuries in an accident caused by a driver ofthe vehicle for which a policy had been taken out by the injured person being atthe same time a policyholder. Should the EU law protect also those persons who are clearly attempting tomisuse an insurance contract? Shall we slur over the fact that by its nature an insurance contract has always been based onmutual trust (uberrimae fidei contract)? Should the rules governing motor third party liability insurance go as far as in no other insurance? Do fraudsters deserve protection? Keywords

Caffeine Attenuates Exacerbated Central Fatigue during Moderate-Intensity Cycling Exercise in Women with Fibromyalgia.

To compare the development of fatigability during a moderate-intensity cycling exercise between women with fibromyalgia (FM) and control women (CON) after acute ingestion of caffeine and placebo. Ten FM and 10 CON women performed a 30-min moderate-intensity cycling exercise 1 h after the ingestion of a capsule containing either caffeine or a placebo. Fatigability and its central and peripheral determinants were determined via changes from pre- to post-15 and post-30 min of exercise in maximal voluntary isometric contractions, voluntary activation (VA), and quadriceps potentiated twitch torque ( Qtw-pot ), respectively. Heart rate, muscle oxygen saturation, perceptive responses, mood state, localized and widespread pain, and sleepiness were also monitored during and after exercise. There was a time versus group interaction for maximal voluntary isometric contraction and VA ( P < 0.001) but not for Qtw-pot ( P = 0.363), indicating a greater rate of fatigability development, mainly caused by central mechanisms, in the FM than in the CON group. There was also a main effect of condition for VA ( P = 0.011), indicating that caffeine attenuates central mechanisms of fatigability in both groups. Caffeine ingestion also increased muscle oxygenation, perceived vigor, and energy, and decreased leg muscle pain, sleepiness, and perceived fatigue in both groups. However, caffeine improved perceived pleasure/displeasure and exercise adherence likelihood only in the FM group. Compared with CON, women with FM present a greater rate of fatigability during exercise, mainly of central origin. Caffeine seems to be a promising bioactive to counteract the central mechanisms of fatigability and improve the exercise experience among FM women.

RIGHT VENTRICLE IN PATIENTS WITH ARTERIAL HYPERTENSION AND B STAGE HEART FAILURE

Objective: According to ACC/AHA Heart failure (HF) classification the A stage of HF is a high risk for HF but without structural heart disease or symptoms; B stage is a structural heart disease but without signs or symptoms of HF. One of the most important risk factors of HF is Arterial Hypertension (AH). There is no information about Right Ventricular (RV) structure and function, in patients with stage A and B of HF. The aim of our research was to study RV structure and function in patients with AH and stage A or B HF. Design and method: We studied 163 patients with AH (female-76, male 87). 45 in stage A and 118 in stage B HF. All patients undergone standard EchoCG examination. RV outflow tract (RVout) was examined by M-mode from parasternal short axis and PW TDI from subcostal position (RVoutTDI). The shape of RWoutTDI was different from the Tricuspid anulus TDI. It consists from positive isometric contraction (ICTs), isotonic contraction (s), negative early diastolic (e) late (a) diastolic waves velocities, two negative (e1) positive (e2) isometric relaxation waves. We measured the pick velocities of these waves in cm/sec and isometric contraction (ICT), ejection (RVET) and isometric relaxation time (IRT) intervals in msec. On M-mode EcoCG of RVoutRV we measured Diastolic Diameter (Dd) systolic diameter (Ds), fractional shortening (RWoutFS) and RW wall systolic excursion (RWexc). Results: We did not find any significant differences between in RV EcoCG, RVout, RVoutTRI and Tricuspid annulus TDI parameters between the A and B Heart Failure groups in patients wit Arterial Hypertension. Conclusions: There is no difference in EchoCG parameters between A and B Heart Failure groups in patients with Arterial Hypertension.

Contrasting effects of increasing dissolved iron on photosynthesis and O2 availability in the gastric cavity of two Mediterranean corals.

Iron (Fe) plays a fundamental role in coral symbiosis, supporting photosynthesis, respiration, and many important enzymatic reactions. However, the extent to which corals are limited by Fe and their metabolic responses to inorganic Fe enrichment remains to be understood. We used respirometry, variable chlorophyll fluorescence, and O2 microsensors to investigate the impact of increasing Fe(III) concentrations (20, 50, and 100 nM) on the photosynthetic capacity of two Mediterranean coral species, Cladocora caespitosa and Oculina patagonica. While the bioavailability of inorganic Fe can rapidly decrease, we nevertheless observed significant physiological effects at all Fe concentrations. In C. caespitosa, exposure to 50 nM Fe(III) increased rates of respiration and photosynthesis, while the relative electron transport rate (rETR(II)) decreased at higher Fe(III) exposure (100 nM). In contrast, O. patagonica reduced respiration, photosynthesis rates, and maximum PSII quantum yield (Fv/Fm) across all iron enrichments. Both corals exhibited increased hypoxia (<50µmol O2 L-1) within their gastric cavity at night when exposed to 50 and 100 nM Fe(III), leading to increased polyp contraction time and reduced O2 exchange with the surrounding water. Our results indicate that C. caespitosa, but not O.patagonica, might be limited in Fe for achieving maximal photosynthetic efficiency. Understanding the multifaceted role of iron in corals' health and their response to environmental change is crucial for effective coral conservation.

Motor unit discharge rate modulation during isometric contractions to failure is intensity- and modality-dependent.

The physiological mechanisms determining the progressive decline in the maximal muscle torque production capacity during isometric contractions to task failure are known to depend on task demands. Task-specificity of the associated adjustments in motor unit discharge rate (MUDR), however, remains unclear. This study examined MUDR adjustments during different submaximal isometric knee extension tasks to failure. Participants performed a sustained and an intermittent task at 20% and 50% of maximal voluntary torque (MVT), respectively (Experiment 1). High-density surface EMG signals were recorded from vastus lateralis (VL) and medialis (VM) and decomposed into individual MU discharge timings, with the identified MUs tracked from recruitment to task failure. MUDR was quantified and normalised to intervals of 10% of contraction time (CT). MUDR of both muscles exhibited distinct modulation patterns in each task. During the 20% MVT sustained task, MUDR decreased until ∼50% CT, after which it gradually returned to baseline. Conversely, during the 50% MVT intermittent task, MUDR remained stable until ∼40-50% CT, after which it started to continually increase until task failure. To explore the effect of contraction intensity on the observed patterns, VL and VM MUDR was quantified during sustained contractions at 30% and 50% MVT (Experiment 2). During the 30% MVT sustained task, MUDR remained stable until ∼80-90% CT in both muscles, after which it continually increased until task failure. During the 50% MVT sustained task the increase in MUDR occurred earlier, after ∼70-80% CT. Our results suggest that adjustments in MUDR during submaximal isometric contractions to failure are contraction modality- and intensity-dependent. KEY POINTS: During prolonged muscle contractions a constant motor output can be maintained by recruitment of additional motor units and adjustments in their discharge rate. Whilst contraction-induced decrements in neuromuscular function are known to depend on task demands, task-specificity of motor unit discharge behaviour adjustments is still unclear. In this study, we tracked and compared discharge activity of several concurrently active motor units in the vastii muscles during different submaximal isometric knee extension tasks to failure, including intermittent vs. sustained contraction modalities performed in the same intensity domain (Experiment 1), and two sustained contractions performed at different intensities (Experiment 2). During each task, motor units modulated their discharge rate in a distinct, biphasic manner, with the modulation pattern depending on contraction intensity and modality. These results provide insight into motoneuronal adjustments during contraction tasks posing different demands on the neuromuscular system.

Characteristics of Changes in Contractile Properties of Muscle after Anaerobic Exercise

Tensiomyography (TMG) has been described as an effective method for identifying differences in muscle response to athletic training stimuli. However, there is a lack of studies that evaluated changes in muscle contractile properties in response to anaerobic effort and related these changes to Wingate test parameters in more than one lower limb superficial muscle. The main contribution of this work is to evaluate changes in the contractile properties of muscles in response to anaerobic exercise. In a group of 20 physically active men, the body composition analysis was performed using a Tanita DC-360 device. The anaerobic effort was assessed by a Wingate test (30 s), and the contractile properties of muscles were measured using a TMG S2 device. The TMG parameters were measured in selected superficial muscles of the dominant lower limb. The study also calculated indices of the differences (d) and the size of the effect (r). An anaerobic effort in the form of the Wingate test resulted in greater stiffness (Dm) in the vastus lateralis muscle (p = 0.0365; r = 0.47) and a delayed response to stimulus (Td) in the vastus lateralis (p = 0.0239; r = 0.51) and vastus medialis (p = 0.0031; r = 0.66) muscles. The half relaxation time (Tr) (p = 0.0478; r = 0.44) and sustained contraction time (Ts) (p = 0.0276; r = 0.49) in the rectus femoris muscle were also increased. In contrast, a prolonged stimulus-response time (Td) with a decrease in sustained contraction time (Ts) was observed in the gastrocnemius lateralis (Td: p = 0.0054; r = 0.64 and Ts: p = 0.0012; r = 0.74) and gastrocnemius medialis (Td: p = 0.0229; r = 0.52 and Ts: p = 0.0054; r = 0.64) muscles. A significant decrease in contraction time (Tc) (p = 0.0051; r = 0.63) occurred only in the soleus muscle. In addition, significant correlations were shown between selected changes in contractile properties of muscle and parameters of the Wingate anaerobic test. Anaerobic exercise has a significant effect on changes in skeletal muscle contractility parameters. TMG is an effective method for identifying differences in muscle response to sports training stimuli.

Serial tissue Doppler imaging in the evaluation of bronchopulmonary dysplasia-associated pulmonary hypertension among extremely preterm infants: a prospective observational study.

To evaluate serial tissue Doppler cardiac imaging (TDI) in the evolution of bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH) among extremely preterm infants. Prospective observational study. Single-center, tertiary-level neonatal intensive care unit. Infant born <28 weeks gestation. Utility of TDI in the early diagnosis and prediction of BPD-PH and optimal timing for screening of BPD-PH. A total of 79 infants were included. Of them, 17 (23%) had BPD-PH. The mean gestational age was 25.9 ± 1.1 weeks, and mean birth weight was 830 ± 174 g. The BPD-PH group had a high incidence of hemodynamically significant patent ductus arteriosus (83% vs. 56%, p < 0.018), longer oxygen days (96.16 ± 68.09 vs. 59.35 ± 52.1, p < 0.008), and prolonged hospital stay (133.8 ± 45.9 vs. 106.5 ± 37.9 days, p < 0.005). The left ventricular eccentricity index (0.99 ± 0.1 vs. 1.1 ± 0.7, p < 0.01) and the ratio of acceleration time to right ventricular ejection time showed a statistically significant trend from 33 weeks (0.24 ± 0.05 vs. 0.28 ± 0.05, p < 0.05). At 33 weeks, the BPD-PH group showed prolonged isovolumetric contraction time (27.84 ± 5.5 vs. 22.77 ± 4, p < 0.001), prolonged isovolumetric relaxation time (40.3 ± 7.1 vs. 34.9 ± 5.3, p < 0.003), and abnormal myocardial performance index (0.39 ± 0.05 vs. 0.32 ± 0.03, p < 0.001). These differences persisted at 36 weeks after conceptional gestational age. TDI parameters are sensitive in the early evolution of BPD-PH. Diagnostic accuracy can be increased by combining the TDI parameters with conventional echocardiographic parameters. BPD-PH can be recognizable as early as 33-34 weeks of gestation.

Effects of 4-week circuit strength combined with blood flow restriction training on muscle status and performance in Taekwondo athletes

This study explored the effects of a 4-week circuit strength training with blood flow restriction on Taekwondo athletes. Six male athletes (age 20.6 ± 1.85, height 184.3 ± 7.63 cm, training duration 7.5 ± 2.07 years) were assessed for explosive strength, muscle recruitment, and sport-specific skills. The regimen encompassed evaluations of lower limb power, Isokinetic strength, force via electronic kicks, and Tensiomyography (TMG) measurements pre-and post-training. Outcomes revealed enhanced jumping abilities, improved knee muscles, and superior kicking skills. There was a notable increase in muscle fibre recruitment and a shift towards type II muscle fibres. Medial thigh muscle displacement showed a positive correlation with jump duration, while lateral thigh muscles indicated a connection with kick numbers. The regimen notably improved explosive power, muscle fibre distribution, and reduced muscle contraction times. Yet, no significant changes in lower limb bilateral symmetry or the link between TMG parameters and athletic prowess were observed.

TIME AND COST ANALYSIS OF DHOHO KEDIRI AIRPORT ACCESS ROAD PROJECT USING EARNED VALUE METHOD

Delays in project completion are something that any project contractor must avoid. Because apart from having a negative effect on the credibility of the project contractor, delays in project completion also cause penalty costs to be borne by the contractor, so that the profits to be obtained are reduced.Earned Value Method. This method is used to determine project performance in terms of costs at one time, determine project performance in terms of schedule/time at one time, predict costs to complete the project after the evaluation time and predict the time to complete the project after the evaluation.By using this method in the Kediri airport access road construction project, it was found that the project was delayed from the plan. The ETC (estimate to complete) value obtained was the estimated budget value required for completion was IDR 17,470,510,292.77, while the EAC (estimate at complete) value obtained was the final total cost estimate. project is IDR 32,509,153,464.05. TE Value Results (Time Estimate) to complete the project to completion in 89 calendar days or 5 days later than the contract time of 84 calendar days.

A new Doppler index, cerebro-placental-uterine ratio, and fetal cardiac parameters in early onset preeclampsia.

Our aim was to investigate the significance of cerebro-placento-uterine ratio CPUR, a new Doppler index, and fetal cardiac parameters (Mod MPI, EFT) in early-onset preeclampsia (EOPE) and to examine whether these parameters are related to perinatal outcome. Forty participants diagnosed with EOPE (preeclampsia cases diagnosed before 34 weeks of gestation) and 40 healthy pregnant women were included in this study. Demographic data were recorded. Doppler parameters such as middle cerebral artery (MCA), umbilical artery (UA), and uterine artery (Ut-A), and left modified myocardial performance index (Mod-MPI) and epicardial fat thickness (EFT) were measured. Cerebroplacental ratio (CPR) was determined by dividing MCA pulsatility index (PI) by UA PI. CPUR was calculated as the ratio of CPR to mean UtA-PI (CPUR = CPR/UtA-PI). All parameters were compared between the EOPE and control groups. Correlation tests were used to examine the relationship between Doppler parameters and perinatal outcome. p values less than 0.05 were considered statistically significant. The pulsatility index of the middle cerebellar artery, CPUR and CPR values were statistically lower in the EOPE group than in the control group (p = 0.002; p = <0.001; p = <0.001; respectively). No statistical differences were found between groups for isovolumetric contraction time (ICT), isovolumetric relaxation time (IRT), ejection time (ET), left mod-MPI, EFT (p = 0.117; p = 0.093; p = 0.398; p = 0.882; p = 0.202, respectively). Umbilical artery Doppler pulsatility index (PI), mean uterine artery Doppler pulsatility index (PI), were higher in the EOPE group than in the control group (p = 0.006; and p = <0.001, respectively). The CPUR value for predicting EOPE was ≤1.3652 with 74. 4% sensitivity and 94.9% specificity. Positive correlations were found between CPUR, CPR, and some neonatal parameters. CPUR, a new index combining fetal and uterine Doppler indices, may add contribution to predict adverse perinatal outcome and EOPE.

Metabolic Consequences of Anabolic Steroids, Insulin, and Growth Hormone Abuse in Recreational Bodybuilders: Implications for the World Anti-Doping Agency Passport

BackgroundHormonal doping in recreational sports is a public-health concern. The World Anti-Doping Agency (WADA) promoted the creation of the Athlete Biological Passport, aiming to monitor athlete’s biological variables over time to facilitate indirect detection of doping. Detection tests for anabolic androgenic steroids (AAS) and growth hormone (GH) are available while insulin abuse cannot be revealed. We have determined in recreational bodybuilders the metabolic effects associated with different patterns of hormone abuse. All analyses were conducted using Statistical Package for Social Sciences (SPSS) 21.0 software (SPSS Chicago, IL).ResultsWe have assessed plasma concentrations of selected metabolic markers and fatty acid content in erythrocyte membranes of 92 male bodybuilders and in 45 healthy controls. Hormonal abuse was identified by anonymous questionnaires. 43% (%) of recruited bodybuilders regularly abused hormones, i.e., anabolic androgenic steroids (95%) often associated with GH (30%) and/or insulin (38%). HDL-cholesterol was lower in insulin and/or GH abusers. Alanine (ALT) and aspartic (AST) transaminases were greater in hormone abusing bodybuilders than in non-doping bodybuilders and controls. Insulin doping was selectively associated with increased plasma ALT-to-AST ratio. In erythrocyte membranes, elongase activity (i.e., stearic-to-palmitic ratio) was lower in insulin and/or growth hormone doping, whereas increased Δ-9 desaturase activity (i.e., palmitoleic-to-palmitic ratio) was selectively associated with insulin doping.ConclusionsIn conclusion, our study demonstrates that insulin and GH abuse are characterized by multiple alterations of specific metabolic markers. Although further studies are needed to test whether longitudinal monitoring of selected metabolic marker such as muscle contraction time, HDL levels, ALT-AST ratio as well as the activities of selected enzymes (e.g. Δ-9 desaturase and elongase), could contribute to the detection of insulin and GH abuse in sport.

Starters vs. non-starters differences in vertical jump force-time metrics in female professional volleyball players.

As one of the fundamental volleyball skills, countermovement vertical jump (CMJ) has been commonly implemented in the applied sports setting as a non-invasive and time-efficient assessment of athletes' lower-body neuromuscular function. The purpose of the present study was to examine the differences in CMJ characteristics between starters and non-starters within a cohort of professional female volleyball players. Nineteen athletes competing in one of the top European leagues (i.e., SuperLeague) volunteered to participate in the present investigation. Following the completion of a warm-up protocol, each athlete performed three maximal-effort CMJs with no arm swing while standing on a uni-axial force plate system sampling at 1,000 Hz. The following force-time metrics were used for performance analysis purposes: braking phase duration and impulse, eccentric and concentric duration, mean and peak force and power, contraction time, jump height, and reactive strength index-modified. Mann-Whitney U and independent t-tests revealed no statistically significant differences (p > 0.05) during both eccentric and concentric phases of CMJ between the players included in the starting lineup (n = 9) and their substitutions (n = 10), with the effect sizes being small to moderate in magnitude (g = 0.053-0.683). While further research is warranted on this topic, these results suggest that securing a position in a starting lineup at the professional level of volleyball play may be more contingent on the player's ability to proficiently execute sport-specific skills (e.g., blocking, attacking), rather than the performance on the CMJ assessment, considering that the observed values for both groups fall within the desired ranges for this specific population of athletes.

Real-Time Evaluation of Absolute, Cytosolic, Free Ca2+ and Corresponding Contractility in Isolated, Pressurized Lymph Vessels.

The lymphatic vasculature, now often referred to as "the third circulation," is located in many vital organ systems. A principal mechanical function of the lymphatic vasculature is to return fluid from extracellular spaces back to the central venous ducts. Lymph transport is mediated by spontaneous rhythmic contractions of lymph vessels (LVs). LV contractions are largely regulated by the cyclic rise and fall of cytosolic, free calcium ([Ca2+]i). This paper presents a method to concurrently calculate changes in absolute concentrations of [Ca2+]i and vessel contractility/rhythmicity in real time in isolated, pressurized LVs. Using isolated rat mesenteric LVs, we studied changes in [Ca2+]i and contractility/rhythmicity in response to drug addition. Isolated LVs were loaded with the ratiometric Ca2+-sensing indicator Fura-2AM, and video microscopy coupled with edge-detection software was used to capture [Ca2+]iand diameter measurements continuously in real time. The Fura-2AM signal from each LV was calibrated to the minimum and maximum signal for each vessel and used to calculate absolute [Ca2+]i. Diameter measurements were used to calculate contractile parameters (amplitude, end diastolic diameter, end systolic diameter, calculated flow) and rhythmicity (frequency, contraction time, relaxation time) and correlated with absolute [Ca2+]i measurements.

Explanatory Model for Elite Canoeists’ Performance Using a Functional Electromechanical Dynamometer Based on Detected Lateral Asymmetry

Canoe modality in flatwater canoeing has a clear asymmetrical nature. This study aimed (1) to determine the magnitude and direction of neuromuscular properties, range of motion (ROM) and lower-limb strength asymmetries in female and male canoeists; (2) to establish sex-individualized asymmetry thresholds for canoeists’ neuromuscular properties, ROM and lower-limb strength; and (3) to determine the relationship of canoeists’ neuromuscular properties, ROM and lower-limb strength asymmetries with a specific canoe–dynamometer performance test. Twenty-one international canoeists were assessed through tensiomyography (TMG), ROM, lower-limb explosive strength, and a specific canoe incremental dynamometric test. The magnitude of asymmetry assessed through TMG and ROM was not modulated either by sex or performance level (international medal vs. non-medal). Females showed greater asymmetry than males on muscle tone of the erector spinae towards non-stroke side (22.75% vs. 9.72%) and the tibialis anterior (30.97% vs. 16.29%), and Fmax in explosive leg press (2.41% vs. 0.63%) towards the stroke side. International medalists showed greater asymmetry in semitendinosus contraction time towards non-stroke side (20.51% vs. 9.43%) and reached Vmax earlier in explosive leg press towards stroke side leg (19.20% vs. 9.40%). A greater asymmetry in Fmax and in Vm, and a smaller asymmetry in Tvmax and in leg press showed a small predictive capacity for canoeists’ performance on a specific canoe incremental dynamometry test. Reporting reference data from world-class canoeists’ asymmetries can be of great importance for coaches to periodically control lateral asymmetry.

Cardiac functions and pericardial thickness changes in familial Mediterranean fever patients

BackgroundThe goal of the study is to ascertain how the pericardium and heart functions alter in patients with familial Mediterranean fever (FMF) both during the acute phase and the period of subclinical inflammation.MethodsDuring the study, 99 patients diagnosed with FMF (35 of whom were in an FMF attack period) were recruited to this study, and 24 completely healthy children in the same age group—who did not have FMF and had not any cardiac condition that applied to visit the pediatric cardiology outpatient clinic for routine follow-up—were included as the control group.ResultsIn patients with FMF, there was no discernible relationship between genetic abnormalities and pericardial thickness (p > 0.05). A significant difference was not observed in the diastolic and systolic cardiac function values between the control group and the FMF patients, with the exception of the parameters related to ejection time (ET), contraction time (IVCT), and relaxation time (IVRT). It was observed that pericardial thickness was greater in FMF patients than in study participants who did not have FMF, and this difference is statistically significant (p < 0.05).ConclusionsIt was determined that the effects of cardiac inflammation continued in children with FMF, even if they were asymptomatic. Therefore, it should be part of the follow-ups.Key points• In our study, cardiac functions and pericardial thickening of 99 FMF patients with and without attack were prospectively investigated.• In ongoing follow-up of patients with FMF, we found that inflammation, which affects all serosas, also affects the pericardium during the attract and nonattack phase.• We believe that cardiac functions, including the status of the pericardium, should be monitored as part of the long-term follow-up of FMF.

Successful Powerlifting in a Unilateral, Transtibial Amputee: A Descriptive Case Series.

Beausejour, JP, Guinto, G, Artrip, C, Corvalan, A, Mesa, MF, Lebron, MA, and Stock, MS. Successful powerlifting in a unilateral, transtibial amputee: A descriptive case series. J Strength Cond Res 38(5): e243-e252, 2024-There are no reports in the literature of powerlifting success after amputation. We had the unique opportunity to characterize functional outcomes, strength, muscle contractility and size, and corticospinal excitability in an accomplished, competitive powerlifter (best competition squat = 205.0 kg, deadlift = 262.7 kg) with a unilateral, transtibial amputation relative to amputee controls. Four men (age range = 23-49 years) with unilateral, lower-limb amputation (3 transtibial, 1 transfemoral) participated in 1 laboratory visit. We assessed 10-m gait speed, the timed up and go (TUG) test, 5-time sit-to-stand performance (5TSTS), contractile properties of the vastus lateralis (VL) and medial gastrocnemius by tensiomyography, and VL cross-sectional area (CSA) by ultrasonography. Unilateral assessments for the intact limb included isokinetic knee extension and flexion torque and power and transcranial magnetic stimulation derived corticospinal excitability. An interview with the powerlifter provided contextual perspective. Compared with the control subjects, the powerlifter performed the 5TSTS faster (6.8%), exhibited faster VL contraction times (intact limb = 12.2%; residual limb = 23.9%), and showed larger VL CSA for the intact limb (46.7%). The powerlifter exhibited greater knee extension and flexion peak torque and mean power, particularly at 180°·s -1 , as well as greater corticospinal excitability for the intact VL (65.6%) and tibialis anterior (79.6%). By contrast, the control subjects were faster in the TUG (18.3%) and comfortable (13.0%) and fast (21.4%) in the 10-m walk test. The major themes of our interview included needing to modify lifting mechanics, persistence, and remarkable pain tolerance. Our findings highlight the impressive neuromuscular adaptations that are attainable after lower-limb amputation.

Evaluation of skeletal muscle function in male rats with doxorubicin-induced myopathy following various exercise techniques: the significant role of glucose transporter 4

A common anthracycline antibiotic used to treat cancer patients is doxorubicin (DOX). One of the effects of DOX therapy is skeletal muscle fatigue. Our goal in this research was to study the beneficial effect of exercise on DOX-induced damaged muscle fibers and compare the effect of different exercise strategies (prophylactic, post- toxicity and combined) on DOX toxicity. Five groups were created from 40 male rats: group I, control group; group II, DOX was administered intraperitoneally for 2 weeks over 6 equal injections (each 2.5 mg/kg); group III, rats trained for 3 weeks before DOX; group IV, rats trained for 8 weeks after DOX; and group V, rats were trained for 3 weeks before DOX followed by 8 weeks after. Measures of oxidative damage (H2O2, catalase), inflammation (TNF-α), and glucose transporter 4 (GLUT4) expression on skeletal muscle were assessed. Also, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) was estimated. Skeletal performance was evaluated by contraction time (CT), half relaxation time (1/2 RT), and force-frequency relationship by the end of this research. The current study demonstrated a detrimental effect of DOX on skeletal performance as evidenced by a significant increase in CT and 1/2 RT compared to control; in addition, H2O2, TNF-α, and HOMA-IR were significantly increased with a significant decrease in GLUT4 expression and catalase activity. Combined exercise therapy showed a remarkable improvement in skeletal muscle performance, compared to DOX, CT, and 1/2 RT which were significantly decreased; H2O2 and TNF-α were significantly decreased unlike catalase antioxidant activity that significantly increased; in addition, skeletal muscle glucose metabolism was significantly improved as GLUT4 expression significantly increased and HOMA-IR was significantly decreased. Exercise therapy showed significant improvement in all measured parameters relative to DOX. However, combined exercise therapy showed the best improvement relative to both pre-exercise and post-exercise groups.